This invention relates to a roof plate for longitudinal roofing, and more particularly to a roof plate for longitudinal roofing which is made of a metal material and formed into a predetermined length in a longitudinal direction of a roof or an eaves-ridge direction.
The words "longitudinal direction", "longitudinal" and "longitudinally" used herein in connection with a roof, roofing, a roof plate and the like each indicate an eaves-ridge direction, or a direction extending from eaves of a roof to a ridge thereof or from the ridge to the eaves and the words "lateral direction", "lateral" and "laterally" indicate a direction perpendicular to the longitudinal direction.
A roof plate is generally classified into a roof plate for longitudinal roofing and that for lateral roofing. The present invention is directed to a roof plate for longitudinal roofing.
The roof plate for longitudinal roofing is formed into a substantially rectangular shape, as well as a predetermined length in the longitudinal direction. A plurality of such roof plates for longitudinal roofing thus formed are connected to each other according to any one of two roofing procedures for the purpose of forming or assembling a roof structure. One of the procedures is so carried out that the roof plates for longitudinal roofing are connected to each other in order in the lateral direction by means of fixtures to form a first or lowermost lateral-extending roof plate row and then a second or next laterally-extending roof plate row which is longitudinally adjacent to the first roof plate row is likewise formed while longitudinally connecting the roof plates of the first roof plate row formed to the roof plates of the second one being formed which positionally correspond to each other in the longitudinal direction. In this roofing procedure, the above-described operations are successively repeated in a ridge direction, to thereby form a roof.
The other roofing procedure is carried out in such a manner that a plurality of the roof plates for longitudinal roofing are longitudinally connected to each other in turn to form a first or outermost roof plate row longitudinally extending. Then, a second or next longitudinal roof plate row is likewise formed and thereafter the roof plate rows which are thus formed and laterally adjacent to each other are laterally connected to each other. In the second procedure, the above-described operations are repeated, resulting in a roof being assembled.
Longitudinal connection between the roof plates may be carried out in such a manner as disclosed in Japanese Utility Model Application Laid-Open Publication No. 134123/1990. More particularly, a roof plate includes a substantially flat plate body provided with a ridge side engagement, which is formed with a plurality of strip-like projections. The strip-like projections are overlappedly engaged with an eaves side engagement portion of a roof plate which is adjacent in a ridge direction to longitudinally connect the adjacent roof plates to each other. Also, Japanese Patent Application Laid-Open Publication No. 86615/1989 and Japanese Patent Application Laid-Open Publication No. 8444/1990 each disclose another longitudinal connection between roof plates for longitudinal roofing in which longitudinal connection ends of each of the roof plates each are provided with a level different portion. The connection is carried out by means of a tongue-like element, through which longitudinally adjacent roof plates are overlapped each other for the longitudinal connection. Also, a joint made of a rubber material is incorporated in a space defined in the level different portions overlapped, to thereby ensure water-tightness at a longitudinal connection region between the roof plates.
Nevertheless, the prior art causes rainwater to easily enter the connection region through the overlapped portion, because both roof plates are merely connected by overlapping.
Also, the above-described longitudinal connection carried out by overlapping between the roof plates through the level different portion causes a level difference to be formed on the appearance of a roof, to thereby fail to form a planar roof surface, as indicated in Japanese Patent Application Laid-Open Publication No. 194244/1990 which discloses a roof plate for longitudinal roofing. More particularly, the longitudinal connection, when rain and wind blow against the longitudinal connection region, causes rainwater to enter the connection region. This is substantially promoted by the level different portion at the longitudinal connection region because the level difference portion causes a slope or pitch of a roof to be at least locally reduced. In particularly, when the pitch is gentle, the level different portion often causes the pitch to be reverse. Thus, it is required to set a pitch of a roof sufficient to prevent back draft of a roof due to the level different portion.
Further, the roof plate disclosed in Japanese Patent Application Laid-Open Publication No. 194244/1990 fails to permit a longitudinal connection region between the roof plates to exhibit sufficient strength against a wind pressure, so that an eaves side end of each of the roof plates is lifted by rainstorm to form a gap therebetween, resulting in leakage of rainwater through the gap. In addition, the eaves side end of the roof plate is formed into a height smaller than each of lateral rising connection sections thereof, to thereby cause a gap to be formed due to a difference in height therebetween, resulting in leakage of rainwater through the gap. Thus, the roof plate of the Japanese publication fails to exhibit satisfactory water-tightness.